go-opentelemetry

Getting Started

You can find a getting started guide on opentelemetry.io.

OpenTelemetry's goal is to provide a single set of APIs to capture distributed traces and metrics from your application and send them to an observability platform. This project allows you to do just that for applications written in Go. There are two steps to this process: instrument your application, and configure an exporter.

Dependency

• Gin Web Framework
• Open Telemetry
• GoDotEnv by joho

Install

Go Version 1.16+

go get github.com/erajayatech/go-opentelemetry

Setup Environment

• Set the following environment variables:

• MODE=<your_application_mode>
  • Example : prod
• APP_VERSION=<your_application_version>
• APP_NAME=<your_application_name>
• OTEL_EXPORTER_OTLP_ENDPOINT=https://otlp.nr-data.net:4317
• OTEL_EXPORTER_OTLP_HEADERS="api-key=<your_license_key>"
  • Replace <your_license_key> with your Account License Key.
• OTEL_SAMPLED=true
  • Be careful about using this sampler in a production application with significant traffic: a new trace will be started and exported for every request. If you won't sampling for every request just set to false

How To Use

• Import package on main.go

otel "github.com/erajayatech/go-opentelemetry"

• Add below code to main.go

otelTracerService := otel.ConstructOtelTracer()
otelTracerServiceErr := otelTracerService.SetTraceProviderNewRelic(ctx)
if otelTracerServiceErr != nil {
    panic(otelTracerServiceErr)
}

• Tracing Controller

  • Import package

  otel "github.com/erajayatech/go-opentelemetry"

  • Start Span Tracer

  ctx, span := otel.Start(context)
  defer span.End()

  • Use code below to add span's tags

  otel.AddSpanTags(span, map[string]string{"traceId": singleton.Trace().ID, "RegisterRequest": string(requestMarshalled)})

  • Use code below to add span error

  if err != nil {
      otel.AddSpanError(span, err)
      otel.FailSpan(span, "Request not valid")
      httpresponse.BadRequest(context, "Request not valid")
      return
  }

• Tracing Service

  • Import package

  otel "github.com/erajayatech/go-opentelemetry"

  • Add context argument to function that we want to trace, example :

  func (service *RegisterService) Register(context context.Context, request RegisterRequest, platform string) *httpresponse.HTTPError {}

  • Use code below for add span

  ctx, span := otel.NewSpan(context, "authregister.service.Register", "")
  defer span.End()

  • Use code below to add span error

  if registeredPlatforms.Id == 0 {
      httpError.Code = http.StatusBadRequest
      httpError.Message = "Platform not valid"
      otel.AddSpanError(span, valErr)
      otel.FailSpan(span, httpError.Message)
      return &httpError
  }

• Tracing Query

  • Add code below on database.go
    • Import package

    "gorm.io/gorm/logger"
    "gorm.io/plugin/opentelemetry/logging/logrus"
    "gorm.io/plugin/opentelemetry/tracing"

    • Set gorm logger

    logger := logger.New(
        logrus.NewWriter(),
        logger.Config{
            SlowThreshold: time.Millisecond,
            LogLevel:      logger.Warn,
            Colorful:      false,
        },
    )
    
    db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{Logger: logger})
    
    if err != nil {
        log.Println("Connected to database Failed:", err)
    }
    
    if err := db.Use(tracing.NewPlugin()); err != nil {
        panic(err)
    }

  • Add code below on repository
    • Import package

    otel "github.com/erajayatech/go-opentelemetry"

    • Add context argument to function that we want to trace, example :

    func (repo *RegisterRepository) getCustomerByEmail(context context.Context, customer *model.Customer, email string) {}

    • Use code below for add span

    ctx, span := otel.NewSpan(context, "authregister.RegisterRepository.getCustomerByEmail", "")
    defer span.End()

    • Use code below for trace a query

    repo.db.WithContext(ctx).First(customer, "email = ?", strings.ToLower(email))

• Tracing External Service

  • Import package

  otel "github.com/erajayatech/go-opentelemetry"

  • Add context argument to function that we want to trace, example :

  func (capillary *Capillary) sendToStagingCustomer(context context.Context, url string, payload interface{}, stagingResponse *StagingCustomerResponse) (*StagingCustomerResponse, error) {}

  • Use code below for add span

  httpSpanAttribute := otel.HttpSpanAttribute{}
  httpSpanAttribute.Method = request.Method
  httpSpanAttribute.Url = request.RequestURI
  httpSpanAttribute.IP = request.Host
  
  _, span := otel.NewHttpSpan(context, "capillary.sendToStagingCustomer", url, httpSpanAttribute)
  defer span.End()

  • Use code below for add event span

  otel.AddSpanEvents(span, "capillary.sendToStagingCustomer", map[string]string{"traceId": capillary.traceID, "StagCust Endpoint": url, "StagCust Request": string(payloadByte), "StagCustResponse": compactedBuffer.String(), "http.status_code": response.Status})